He listens to Ocelia type speakers using French Phy full range drivers, another good reference in my view.
This blog has already about 30+ articles on Vintage gear, including this one on Elipson, with a BIG claim about the influence of Joseph Leon's contraptions on the rest of us mere cloners of a speaker designer!
If you are a long term reader of this space, you will know that I totally agree with that claim, and I am almost certain that these speakers are still to be bettered for their OVERALL performance and respect of the music.
My first encounter with Elipson in the very early 70s started my journey on hifi excellence and speaker design and they are still my inspiration today almost half a century later. Time and phase alignment, cabinet resonances and size, are still the principles that guides me in any new design.